<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>回调函数</title>
</head>

<body>
  <script>
    // 概念:将函数A作为参数传递给函数B,函数A就叫做回调函数
    function fn() { }
    console.log('回调函数');
    setInterval(fn, 100)
  </script>
</body>

</html>